scholarly journals Population Variation Altered Aggression-associated Oxytocin and Vasopressin Expressions in Brains of Brandt’s Voles in Field Conditions

2021 ◽  
Author(s):  
Shuli Huang ◽  
Guoliang Li ◽  
Yongliang Pan ◽  
Jing Liu ◽  
Jidong Zhao ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Population Density ◽  
Aggressive Behavior ◽  
Brain Regions ◽  
Population Variation ◽  
Field Conditions ◽  
Small Rodents ◽  
Density Dependent ◽  
Inner Mongolia Grassland ◽  
Dependent Change

Abstract Density-dependent change in aggressive behavior is essential for regulating the population dynamics of many small rodents, but the underlying neurological mechanisms have not been examined in field conditions. We hypothesized that aggression-associated oxytocin (OT) and vasopressin (AVP) in specific regions of the brain may be closely related to aggressive behaviors and population changes of small rodents. In this study, we analyzed the associations of OT and AVP expression as well as aggressive behavior with population density of Brandt’s voles in 24 large semi-natural enclosures (0.48 ha for each enclosure) in Inner Mongolia grassland. Then we tested the effects of population density on the OT/AVP system and aggressive behavior in experimentally manipulated populations of Brandt’s voles in the semi-natural enclosures. High density was positively and significantly associated with more aggressive behavior, and increased expression of mRNA and protein of AVP and its receptor, but decreased expression of mRNA and protein of OT and its receptor in specific brain regions of the voles. Our study suggests that OT/AVP systems are important in regulating the density-dependent population dynamics via aggressive behavior of small rodents, and they can be used as indicators of population variation or density-dependent stressors.

scholarly journals Population variation alters aggression-associated oxytocin and vasopressin expressions in brains of Brandt’s voles in field conditions

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Shuli Huang ◽  
Guoliang Li ◽  
Yongliang Pan ◽  
Jing Liu ◽  
Jidong Zhao ◽  
...  
Keyword(s):  
Population Density ◽  
Aggressive Behavior ◽  
Brain Regions ◽  
Population Variation ◽  
Field Conditions ◽  
Small Rodents ◽  
Density Dependent ◽  
Inner Mongolia Grassland ◽  
Crowding Stress ◽  
Dependent Change

AbstractDensity-dependent change in aggressive behavior contributes to the population regulation of many small rodents, but the underlying neurological mechanisms have not been examined in field conditions. We hypothesized that crowding stress and aggression-associated oxytocin (OT) and arginine vasopressin (AVP) in specific regions of the brain may be closely related to aggressive behaviors and population changes of small rodents. We analyzed the association of OT and AVP expression, aggressive behavior, and population density of Brandt’s voles in 24 large semi-natural enclosures (0.48 ha each) in Inner Mongolia grassland. We tested the effects of population density on the OT/AVP system and aggressive behavior by experimentally manipulating populations of Brandt’s voles in the grassland enclosures. High density was positively and significantly associated with more aggressive behavior, and increased expression of mRNA and protein of AVP and its receptor, but decreased expression of mRNA and protein of OT and its receptor in specific brain regions of the voles. Our study suggests that changes in OT/AVP expression are likely a result of the increased psychosocial stress that these voles experience during overcrowding, and thus the OT/AVP system can be used as indicators of density-dependent stressors in Brandt’s voles.

scholarly journals Climatic Factors, Reproductive Success and Population Dynamics in the Montane Vole Microtus Montanus

2005 ◽  
Vol 29 ◽  
pp. 49-51
Author(s):  
Alita Pinter
Keyword(s):  
Population Dynamics ◽  
Reproductive Success ◽  
Population Density ◽  
Climatic Factors ◽  
Small Rodents ◽  
Microtus Montanus ◽  
Small Measure ◽  
Long Term Studies

A variety of hypotheses has been proposed to explain multiannual fluctuations in population density ("cycles") of small rodents (for reviews see Finerty 1980, Taitt and Krebs 1985). Doubtless, such cycles - known since antiquity (Elton 1942) - result from an interaction of a multitude of factors. However, the inability of extant hypotheses, alone or in combination, to explain the causality of cycles rests in no small measure with the fact that long-term studies of the phenomenon are notoriously uncommon.

scholarly journals Climatic Factors, Reproductive Success and Population Dynamics in the Montane Vole, Microtus montanus

1991 ◽  
Vol 15 ◽  
pp. 162-164
Author(s):  
Aelita Pinter
Keyword(s):  
Population Dynamics ◽  
Reproductive Success ◽  
Population Density ◽  
Environmental Variables ◽  
Climatic Factors ◽  
Small Rodents ◽  
Term Study ◽  
Microtus Montanus ◽  
Long Term Study

Multiannual fluctuations in population density ("cycles") of small rodents have been known since antiquity (Elton 1942). Numerous hypotheses have been proposed to explain this phenomenon (for reviews see Finerty 1980, Taitt and Krebs 1985). However, none of these hypotheses, alone or in combination, have been able to explain the causality of cycles. The objectives of this long-term study are to determine whether environmental variables, possibly acting through reproductive responses, contribute to the multiannual fluctuations of the montane vole, Microtus montanus.

scholarly journals Climatic Factors, Reproductive Success and Population Dynamics in the Montane Vole, Microtus montanus

1987 ◽  
Vol 11 ◽  
pp. 103-105
Author(s):  
Aelita Pinter
Keyword(s):  
Population Dynamics ◽  
Reproductive Success ◽  
Population Density ◽  
Environmental Variables ◽  
Climatic Factors ◽  
Small Rodents ◽  
Term Study ◽  
Microtus Montanus ◽  
Long Term Study

Multiannual fluctuations in population density of small rodents have been known since antiquity. However, factors responsible for this phenomenon remain unknown (Krebs and Myers 1974, Finerty 1980, Taitt and Krebs 1985). The objectives of this long-term study are to determine whether environmental variables, possibly acting through reproductive responses, contribute to the multiannual fluctuations of the montane vole, Microtus montanus.

scholarly journals Climatic Factors, Reproductive Success and Population Dynamics in the Montane Vole, Microtus montanus

1988 ◽  
Vol 12 ◽  
pp. 121-124
Author(s):  
Aelita Pinter
Keyword(s):  
Population Dynamics ◽  
Reproductive Success ◽  
Population Density ◽  
Environmental Variables ◽  
Climatic Factors ◽  
Small Rodents ◽  
Term Study ◽  
Microtus Montanus ◽  
Long Term Study

Multiannual fluctuations in population density ("cycles") of small rodents have been known since antiquity (Elton 1942). Numerous hypotheses have been proposed to explain this phenomenon (for reviews see Krebs and Myers 1974, Finery 1980, Taitt and Krebs 1985). However, none of these hypotheses, alone or in combination, can explain the causality of cycles. The objectives of this long-term study are to determine whether environmental variables, possibly acting through reproductive responses, contribute to the multiannual fluctuations of the montane vole, Microtus montanus.

scholarly journals Within and among-population variation in vital rates and population dynamics in a variable environment

2015 ◽  
Author(s):  
Simone Vincenzi ◽  
Marc Mangel ◽  
Dusan Jesensek ◽  
John Carlos Garza ◽  
Alain J Crivelli
Keyword(s):  
Population Dynamics ◽  
Population Density ◽  
Debris Flows ◽  
Life Histories ◽  
Population Variation ◽  
Population Differences ◽  
Vital Rates ◽  
Marble Trout ◽  
Over Time

Understanding the causes of within- and among-population differences in vital rates, life histories, and population dynamics is a central topic in ecology. To understand how within- and among-population variation emerges, we need long-term studies that include episodic events and contrasting environmental conditions, data to characterize individual and shared variation, and statistical models that can tease apart population-, shared-, and individual contribution to the observed variation. We used long-term tag-recapture data and novel statistical and modeling techniques to investigate and estimate within- and among-population differences in vital rates, life histories and population dynamics of marble trout Salmo marmoratus, a endemic freshwater salmonid with a narrow range. Only ten populations of pure marble trout persist in headwaters of Alpine rivers in western Slovenia. Marble trout populations are also threatened by floods and landslides, which have caused the extinction of two populations in recent years. We estimated and determined causes of variation in growth, survival, and recruitment both within and among populations, and evaluated trade-offs between them. Specifically, we estimated the responses of these traits to variation in water temperature, density, sex, early life conditions, and the occurrence of extreme climatic events (e.g., flash floods and debris flows). We found that the effects of population density on traits were mostly limited to the early stages of life and that individual growth trajectories were established early in life. We found no clear effects of water temperature on survival and recruitment. Population density varied over time, with flash floods and debris flows causing massive mortalities and threatening population persistence. Apart from flood events, variation in population density within streams was largely determined by variation in recruitment, with survival of older fish being relatively constant over time within populations, but substantially different among populations. Marble trout show a fast to slow continuum of life histories, with slow growth associated with higher survival at the population level, possibly determined by food conditions and age at maturity. Our work provides unprecedented insight into the causes of variation in vital rates, life histories, and population dynamics in an endemic species that is teetering on the edge of extinction.

Introduction to Population Models

2021 ◽  
pp. 25-46
Author(s):  
Timothy E. Essington
Keyword(s):  
Population Dynamics ◽  
Population Density ◽  
Population Size ◽  
Population Models ◽  
Change Model ◽  
Density Dependent ◽  
Intrinsic Factors ◽  
Model Understanding ◽  
Dynamics Of Populations ◽  
Simple Models

The chapter “Introduction to Population Models” introduces unstructured population models and shows how model decisions can change model behavior, the different ways that feedbacks can be represented, and how one evaluates the consequences of those feedbacks. The goal here is to show how modeling a single entity, population density, can be done in many different ways, depending on the purpose of the model. Understanding the dynamics of populations remains one of the fundamental goals of ecology. Not surprisingly, many models have contributed to the theory of population dynamics and regulation. The models vary considerably in terms of depth, breadth, intended uses (e.g. prediction vs. generality), and structure. This chapter will largely focus on the behavior of simple models, to see how intrinsic factors can dictate variability in population size. Density-independent and density-dependent models are covered, as well as methods used to understand model behaviors.

scholarly journals Climatic Factors, Reproductive Success and Population Dynamics in the Montane Vole, Microtus montanus

1996 ◽  
Vol 20 ◽  
pp. 88-90
Author(s):  
Aelita Pinter
Keyword(s):  
Population Dynamics ◽  
Reproductive Success ◽  
Population Density ◽  
Environmental Variables ◽  
Climatic Factors ◽  
Small Rodents ◽  
Term Study ◽  
Microtus Montanus ◽  
Long Term Study

Multiannual fluctuations in population density ("cycles") of small rodents have been known since antiquity (Elton 1942). Numerous hypotheses have been proposed to explain this phenomenon (for reviews see Finerty 1980, Taitt and Krebs 1985). However, none of these hypotheses, alone or in combination, has been able to explain the causality of cycles. The objectives of this long-term study are to determine whether environmental variables, possibly acting through reproductive responses, contribute to the multiannual fluctuations of the montane vole, Microtus montanus.

scholarly journals Climatic Factors, Reproductive Success and Population Dynamics in the Montane Vole, Microtus montanus

1990 ◽  
Vol 14 ◽  
pp. 94-96
Author(s):  
Aelita Pinter
Keyword(s):  
Population Dynamics ◽  
Reproductive Success ◽  
Population Density ◽  
Climatic Factors ◽  
Small Rodents ◽  
Microtus Montanus

Multiannual fluctuations in population density ("cycles") of small rodents are well known (Elton 1942). Numerous hypotheses have been proposed to explain this phenomenon (for reviews see Krebs and Myers 1974, Finerty 1980, Taitt and Krebs 1985). However, none of these hypotheses, alone or in combination, have been able to explain the causality of cycles.

scholarly journals Climatic Factors, Reproductive Success and Population Dynamics in the Montane Vole, Microtus Montanus

1993 ◽  
Vol 17 ◽  
pp. 84-86
Author(s):  
Aelita Pinter
Keyword(s):  
Population Dynamics ◽  
Reproductive Success ◽  
Population Density ◽  
Environmental Variables ◽  
Climatic Factors ◽  
Small Rodents ◽  
Term Study ◽  
Microtus Montanus ◽  
Long Term Study

Multiannual fluctuations in population density ("cycles") of small rodents have been known since antiquity (Elton 1942). Numerous hypotheses have been proposed to explain this phenomenon (for reviews see Finerty 1980, Taitt and Krebs 1985). However, none of these hypotheses, alone or in combination, have been able to explain the causality of cycles. The objectives of this long-term study are to determine whether environmental variables, possibly acting through reproductive responses, contribute to the multiannual fluctuations of the montane vole, Microtus montanus.

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